Writers Seth Rogen and Evan Goldberg started this script when they were just thirteen years old, because "we just wanted to see if we could write a movie."
Michael Cera's mother actually read the script before he did, and she was the one who convinced him to try out for the part.
During filming, Christopher Mintz-Plasse was the youngest at seventeen, Michael Cera was eighteen, and Jonah Hill was the oldest at twenty-three.
Because Jonah Hill and Seth Rogen are such great friends, they were quoted as saying that when casting Evan, they weren't so much looking for a good actor, as they were "casting for a new best friend."